This invention relates to a hydrocarbyl polyoxyalkylene aminoalcohol and to an internal combustion engine fuel composition containing same.
The combustion of fuel in an internal combustion engine typically results in the formation and accumulation of deposits on various parts of the combustion chamber and on the fuel intake and exhaust systems of the engine. The presence of these deposits in the combustion chamber often result in the following problems: (1) reduction in the operating efficiency of the engine; (2) inhibition in the heat transfer between the combustion chamber and the engine cooling system; and (3) reduction in the volume of the combustion zone which can cause a higher than design compression ratio in the engine. A knocking engine can also result from deposits forming and accumulating in the combustion chamber. A prolonged period of a knocking engine can result in stress fatigue and wear in engine components such as, for example, pistons, connecting rods bearings and cam rods.
The formation and accumulation of intake valve deposits can interfere with valve closing which eventually can result in valve burning. Such deposits can also interfere with valve motion and valve seating which tend to reduce the volumetric efficiency of the engine and limit the maximum design power.
Deposits can also collect in the tubes and runners that are part of the exhaust gas recirculation (EGR) flow. The collection of these deposits can reduce the EGR flow. This will result in a knocking engine and an increase in nitric oxide emissions.
In view of the foregoing problems associated with the formation and accumulation of deposits in the combustion chamber and fuel intake and exhaust systems of an internal combustion engine, efforts have been made to develop fuel additives which will inhibit the deposition of deposits in the engine. Illustrative of such fuel additives are the amido alkanolamines of U.S. Pat. Nos. 5,234,478 and 5,383,942 and the alkylphenoxypolyoxyalkylene amine lactones of U.S. Pat. No. 5,527,364.
In accordance with the present invention, a hydrocarbyl random or block polyoxyalkylene aminoalcohol is provided which possesses the general formula 
wherein R1 is an alkyl, an alicyclic or an alkylalicyclic radical having from about 4 to about 30 carbon atoms or an alkylaryl where the alkyl group is from about 4 to about 30 carbon atoms; x is an integer from 0 to about 5, y is an integer from 1 to about 49, z is an integer from 1 to about 49 and the sum of x+y+z is equal to 3 to about 50; R2 and R3 each is different and is an alkyl group of from 1 to 4 carbon atoms and each oxyalkylene radical can be any combination of repeating oxyalkylene units to form random or block copolymers; R4 is the same as R2 or R3; R5 is hydrogen or 
where R7 is hydrogen or an alkyl group of from 1 to 5 carbon atoms; and R6 is hydrogen or an alkyl group of from 1 to 5 carbon atoms.
It shall be understood herein that the oxyalkylene groups constituting the polyoxyalkylene chain in the foregoing general formula may contain random or block sequencing.
Further in accordance with this invention, a method for the preparation of the foregoing hydrocarbyl polyoxyalkylene aminoalcohol is provided which comprises reacting a hydrocarbyl random or block polyoxyalkylene amine of the general formula 
wherein R1 is an alkyl, an alicyclic or an alkylalicyclic radical having from about 4 to about 30 carbon atoms or an alkylaryl where the alkyl group is from about 4 to about 30 carbon atoms; x is an integer from 0 to about 5, y is an integer from 1 to about 49, z is an integer from 1 to about 49 and the sum of x+y+z is equal to 3 to about 50; R2 and R3 each is different and is an alkyl group of from 1 to 4 carbon atoms and each oxyalkylene radical can be any combination of repeating oxyalkylene units to form random or block copolymers; and R4 is the same as R2 or R3 with a 1,2-epoxide of the general formula 
wherein R6 is hydrogen or an alkyl group of from 1 to 5 carbon atoms to provide the product hydrocarbyl random or block polyoxyalkylene aminoalcohol of the general formula 
wherein R1, R2, R31 R4, R6, x, y and z have the aforestated meanings and R5 is hydrogen or 
wherein R7 is hydrogen or an alkyl group of from 1 to 5 carbon atoms.
Still further in accordance with the present invention, a fuel composition is provided which comprises a major amount of an internal combustion engine fuel and a fuel combustion deposit-inhibiting amount of at least one hydrocarbyl random or block polyoxyalkylene aminoalcohol of the general formula 
wherein R1, R2, R3, R4, R5, R6, x, y and z have the aforestated meanings.
Yet further in accordance with the present invention, a method for inhibiting the deposition of fuel combustion deposits in an internal combustion engine is provided which comprises operating the engine employing as the fuel therefor a fuel composition which comprises a major amount of an internal combustion engine fuel and a fuel combustion deposit-inhibiting amount of at least one hydrocarbyl random or block polyoxyalkylene aminoalcohol of the general formula 
wherein R1, R2, R3, R4, R5, R6, x, y and z have the aforestated meanings.